This invention relates to photosensitive compositions containing an unsaturated polymer, a mercapto acid and a radical initiating system; to elements made from said compositions; and to a process for photoimaging said elements.
Background publications include the following items:
U.S. Pat. No. 4,179,531 discloses a curable composition conprising a monoalkenyl aromatic-diene copolymer resin, a monomer containing a photo-cross-linkable C.dbd.C, a polythiol, and a photoinitiator;
U.S. Pat. No. 4,234,676 discloses a curable composition containing an unsaturated polymer, a monomer, a thiol, and a curing agent;
U.S. Pat. No. 4,248,960 discloses a relief-producing laminate, the under-lamina composition being preferably a photocurable polymer composition;
U.S. Pat. No. 4,266,004 discloses the photoimaging of selected organic sulfide-containing polymers in the presence of oxygen and a photosensitizer;
British Pat. No. 1,390,711 and U.S. Pat. No. 3,767,398 disclose a curable composition consisting of a polymer with recurring units of the monoallyl ester of a methyl vinyl ether/maleic anhydride interpolymer and a polythiol, with or without a photocuring rate accelerator;
U.S. Pat. No. 3,809,633 discloses a chain-extended polythioether-containing polymer composition having reactive unsaturated carbon-carbon functional groups and/or reactive thiol groups within the molecule;
U.S. Pat. No. 3,660,088 discloses a process for etching metal employing a photocurable composition consisting of a polyene, a polythiol, and a photocuring rate accelerator;
U.S. Pat. No. 3,936,530 discloses a curable coating composition which consists of a styrene-allyl alcohol copolymer-based polyene and a polythiol component;
U.S. Pat. No. 3,627,529 discloses a process for preparing a lithographic printing plate from a photocurable composition of an ethylenically unsaturated polyene, a polythiol, and a photocurable rate accelerator;
U.S. Pat. No. 4,179,295 discloses a photosensitive composition containing an organopolysiloxane with aliphatically unsaturated linkages in the molecule and a mercapto-containing organopolysiloxane, the organopolysiloxane cured by irradiation with ultraviolet light to effect cross-linking;
U.S. Pat. No. 4,130,469 discloses a curable coating composition which contains a polymer with pendant mercaptan groups and a bis-maleimide cross-linking agent;
British Pat. No. 1,179,252 discloses the use of butadiene polymers containing carboxyl groups in the preparation of thermoplastic elastomer compositions;
U.S. Pat. No. 2,589,151 discloses thioglycolic acid adducts of butadiene copolymers, prepared in solution using a free-radical initiator; adduct structures being further discussed by Serniuk et al. in J. Am. Chem. Soc., 70, pages 1804 to 1808 (1948);
Marvel et al., Ind. Eng. Chem., 45, pages 2090 to 2093 (1953), disclose the modification of polybutadiene by addition of thiols containing polar groups such as mercaptoacetic acid, to give polymers with improved oil resistance;
Merrill et al., Research Disclosure, 143, page 24 (1976), disclose the use of mercapto acid derivatives of unsaturated polymers as a component in liquid electrographic developers.